SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4318ce2727a0598c7dbfe4272b485860c263360fc3ab60ab912e461963846396' 
  AND token = 'OM5uD9gVfy6Qhs8UTgiqGULiK/YvYiZkGvhg7czh6qw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}